perforation

noun

1. (countable, uncountable)The act of perforating or the state of being perforated.
2. (countable, uncountable)Any opening in a solid object.
3. (countable, uncountable)An abnormal opening in an organ, such as a rupture.
4. (countable, uncountable)A series of holes punched through something in order to assist in separating parts.
5. (countable, uncountable)That portion of a surface that remains after an open disk is removed from it.